Round up decimal number according to fraction in PHP

Question

I am working to convert an excel formula to php function. Now I am facing a problem that is round up as the fraction. Please let me explain it:

(2 * 18)/2.98 = 12.08 but according to my requirement it should be 12.25

(2 * 18.5)/2.98 = 12.416 but according to my requirement it should be 12.50

(2 * 18.8)/2.98 = 12.617 but according to my requirement it should be 12.75

In excel, it is done like :

ceiling(( 2 * 18 )/2.98, 0.25) = 12.25

ceiling(( 2 * 18.5 )/2.98, 0.25) = 12.50

ceiling(( 2 * 18.8 )/2.98, 0.25) = 12.75

I tried in PHP. Ceil() and Floor() do not serve the purpose as these 2 shall give output 13 and 12 accordingly.

Another one round() uses these options PHP_ROUND_HALF_UP, PHP_ROUND_HALF_DOWN, PHP_ROUND_HALF_EVEN, or PHP_ROUND_HALF_ODD which does not serve the purpose.

Anyone there to help me?

This question has been answered here: http://stackoverflow.com/questions/14903379/rounding-to-nearest-fraction-half-quarter-etc — Andreas, Mar 31 '16 at 04:35
@ahossain I just format your question properly. http://stackoverflow.com/posts/36324171/revisions — ketan, Mar 31 '16 at 05:47
@ahossain is none of the answers correct? You should mark the correct answer as accepted and/or upvote. — Andreas, Mar 31 '16 at 06:16
@andreas , yes, none the answer seems right in 100%, all they are partially correct. rather your link has given me proper solution. I used ceil() in replace of floor() for http://stackoverflow.com/questions/14903379/rounding-to-nearest-fraction-half-quarter-etc — naf4me, Mar 31 '16 at 06:37

Sergio Fernandez · Accepted Answer · 2016-03-31T05:08:05.400

1

use this function:

function fractionRound($num,$frac) {
  return ceil($num/$frac)*$frac;
}

call it this way:

echo fractionRound(( 2 * 18 )/2.98, 0.25);

it will round to the nearest 0.25 it will return 12.25

edited Mar 31 '16 at 05:08

answered Mar 31 '16 at 05:00

Sergio Fernandez

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score 0 · Answer 2 · answered Mar 31 '16 at 04:36

PHP only provides facility to round to a precision, with the options that you found. However, you can do something similar to what you want with a little inventive mathematics and a userland function.

Try:

function roundTo($value, $roundTo = 1)
{
    $inverse = 1 / $roundTo;
    return round($value * $inverse) / $inverse;
}

See: https://ideone.com/fojMrS

Note that if you want the ceil or floor functionality you'll have to create versions of this function for ceil and floor, this is just for round.

score 0 · Answer 3 · answered Mar 31 '16 at 04:51

0

$YourNumber = 12.08;
$int = $YourNumber * 4;
$int = ceil($int);

echo $YourNumber ." was the start <br>";
echo $int / 4 ." is the answer";

answered Mar 31 '16 at 04:51

Andreas

23,610
6
30
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score 0 · Answer 4 · answered Mar 31 '16 at 05:50

function roundQuarters($input)
{
    $rm = $input % 0.25;
    return $rm == 0 ? $input : $input - $rm + 0.25;
}

This will round the decimal up to the nearest 0.25, if it's also a divisor of 0.25, it'll return the same. Simple.

And you can replace 0.25 to whatever decimal you want or even parameterize that.

Round up decimal number according to fraction in PHP

4 Answers4

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